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%I #6 Mar 31 2012 12:37:28
%S 1,2,5,12,28,65,158,382,905,2145,5095,12138,28738,68088,161647,383228,
%T 908610,2154138,5108699,12115979,28729086,68134487,161588543,
%U 383218255,908831763,2155346429,5111614446,12122490597,28749145047,68180439683
%N Number of nX1 0..3 arrays with every element value z a city block distance of exactly z from another element value z
%C Column 1 of A209178
%H R. H. Hardin, <a href="/A209173/b209173.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) -5*a(n-2) +6*a(n-3) -14*a(n-4) +21*a(n-5) -36*a(n-6) +80*a(n-7) -97*a(n-8) +80*a(n-9) -86*a(n-10) +109*a(n-11) -49*a(n-12) -53*a(n-13) +137*a(n-14) -123*a(n-15) +86*a(n-16) -193*a(n-17) +172*a(n-18) -118*a(n-19) -50*a(n-20) +59*a(n-21) -161*a(n-22) +255*a(n-23) -218*a(n-24) +448*a(n-25) -280*a(n-26) +177*a(n-27) -132*a(n-28) +33*a(n-29) -88*a(n-30) +128*a(n-31) -22*a(n-32) -13*a(n-33) +61*a(n-34) -79*a(n-35) +33*a(n-36) -21*a(n-37) +8*a(n-38) -3*a(n-39) +4*a(n-40) -4*a(n-41) +a(n-42) -a(n-43)
%e Some solutions for n=8
%e ..3....3....2....0....0....0....0....2....3....1....2....0....1....0....0....0
%e ..0....0....2....1....2....2....1....2....1....1....0....3....1....3....1....1
%e ..2....2....2....1....0....0....1....2....1....1....2....0....0....1....1....1
%e ..3....3....2....0....2....2....1....2....3....1....3....0....1....1....3....1
%e ..2....2....2....0....0....2....1....1....0....0....2....3....1....3....1....1
%e ..1....0....1....1....0....2....2....1....0....2....0....2....1....2....1....1
%e ..1....1....1....1....1....2....0....0....1....0....3....0....1....0....3....0
%e ..1....1....1....1....1....2....2....0....1....2....0....2....1....2....0....0
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 05 2012
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